Turn onto Upper Street and walk to the corner, and then turn right (this is a quiet lane shared with a footpath) and walk to the start of farm buildings and turn right onto the signed footpath. This is an easy track between fields. When you reach the first corner, turn right and then you're good for at least half a mile of walking. When you reach a fork in the path, the left fork will take you downhill to Bushy Common (so uphill on the way back) and the right fork is flat and ends up on a lane where you'll need to turn round.